Heater



May 17 1927 F. P. MUEHLENBECK HEATER l Filed Feb. 11. 1925 ssheets-sheet 1 l 1 I' i zy. L35 Y I l @a I u IF nl l Ff 2 l Q ,39W i oi' i, /0 il l l F lm l I l l @E i i M1? fg N ,Il y g; T

F. P. MUEHLENBECK HEATER May 17, 1927. v 1,629,116

Filed Feb. 11. 1925 5 Sheets-Sheet5 www@ i 20 ried away and Patented May'1927.

UNITED STATES .PATENTOFFICB FEED P. HUEHLENBECK, F CHICAGO, ILLINOIS,ASSIGNOB T0 EUGENE l OF CHICAGO, ILLINOIS.

HEATER.

Application led February 11, 1925. Serial No. 8,475.

This invention relates to improvements in heaters. The invention is hereshown as embodied in a heater especially adapted for industrial useslsuch as for drying enamels,

paints, lacquersand the like, baking castings, ovens, laundries, candryers, wire dryers, and so forth. a

My improved heater is especially adapted for producing recirculationthus saving fuel. By the use of my heater it is possible to lproducerecirculation in ovens where japan, paint, lacquer, and varnishlikeproducts are to be dried. Recirculation in such ovens has heretoforebeen considered impossible 0r quite dangerous due to the fire and theever-present explosive gases. In dryv ing such products combustiblegases are liberated in the process of drying. It has been found that thesooner these vapors are cardrying is effected. My 'improved heater is sodeslgned that it may be made an integral part of a vapor utilizationsystem with com-v plete combustion of the gas fuel taking place 25., inthe first combustion chamber which is a made of circular baiiie brick.Beyond the -rst combustion chamber there is a second combustion chamberbuilt of rectangular fire brick placed horizontally and vertically.

- 30 The combustible vapors and the excess a r required to burn them areintroduced into the heater so that they mingle with the burning gases asthey pass from the first combustion chamber to the second. At this pointi l the products of combustion of the gas fuel lhave attainedsubstantially their highest temperature. l Thus, the fresh air and thecombustible -gases meeting the burning gases, makes it impossible forany dangerous vapors to pass without being instantly consumed. Becauseof this construction, it will be seen that the heater converts anydangerous combustible gases into productive heat and in additioneliminates 'all danger of fire or explosion within the oven. Thisfollows from the fact that the combustible vapors are consumedsubstantially as rapidly as they form.

An observation window is provided on the heater in order to observe thedegree of combustion at all times,ithus enabling the operator toincrease or decrease the air suphazard destroyed, the quicker the plyaccurately. The window is placed where combustion should. be entirelycompleted.

The heater is also equipped with an automatic gas shut-off. 'i

The above mentioned features, and other features and advantages of myinvention will -appear more fully and be described more in detail as I,proceed with my specifil cation.

In that form of device embodying the features of my invention shown inthe accompanying drawings, Figure 1 is a view in side elevation of theheater, Fig.'2 is a top plan view of the same, Fig. 3 is a viewin endeleyation, Fig. 4 is an enlarged view showing 1n detall a part of theautomatic shut-off, Fig. 5 1s a vertlcal sectional view, Fig. V6 is alview taken as indicated by the line 6 of Fig.

5., Fig. 7 is a view taken as indicated by the line 7 of Fig. 5, Fig. 8is a view taken as ind icated by the line 8 of Fig. 5, Fig. 9 is a v1ewtaken as indicated by the line 9 of Fig. 5, and F1g. 10 is a view partlyin side elevation andv partly in section showing the heater connectedtoa drying oven.

C. GMELIN.

In that form of device embodyingth'e fea- I turesI of my invention showninthe accompanylng drawings, tlally rectangular 'casing or shellprovided with the spaced inner and outer walls 11 and 12 respectivelyhaving between them any suitable non-combustible insulating subtance,as, for example, clay, as indicated In one end of the casing 10 there isprovided a smaller axially arranged ractangularly casing 14 made ofsheet metal or other suitable material and constituting a firstcombustion chamber. 4The casing 14 is lined with suitable refractorymaterial, such as fire brick 15 provided with inwardly projectingstaggered alternately vertically and horizontally arranged projectinglugs 16. 16 in order to better mix the 'gases to be burned and in orderto give the products ofv combustion a tortuous passage therethrough.. 17indicates a jet or nozzle through which the fuel is admitted such asilluminating i, gas, natural gas, or other inflammable gas. Surroundingthe nozzle 17 are a series of air inlets 18 adapted to be opened orclosed as desired by the rotatable shutter 19 so that 10 indicates asubstan.

the desired. proportion of gas and air can the space 27 around the firstcombustion be admitted into the first combustion chamber 14. 20indicates a pipe leading to the nozzle 17 through which the gas to beburned is conducted.

At the discharge end of the heater there is provided a blower or fan 21which may be of any desired form and adapted to cause a circulationthrough the heater, so that gases and products of combustion in theheater will be drawn through the same from left to right as viewed inFig. 1 and Fig. 5. The discharge outlet from the fan 21 is connected toa conduit 22 which leads to the bottom of an oven 23 as shown in Fig.10.

In Fig. 10, the arrows indicate the travel of the heated gases andproducts of combustion coming from the heater. `Within the oven l0 theremay be provided any suitable means such as the wire mesh shelves 24 forsupporting the articles to be dried as indicated by 25. 26 indicates aconduit leading from the top of the oven to the heater 10. As clearlyshown in Fig. 5, the conduit 26 enters the. top of the heater 10 abovethe inner combustionchamber 14 which is made smaller than the shell 11thus affording a space 27 between the two.

Beyond the end of the first combustion chamber 14 therevis in the heater10 what may be termed the second combustion chamber as indicated by'28.Within this chamber there are provided staggered alternately arrangedvertical and horizontal bafiie bricks 29 in order to better comminglethe inflammable gases.

Where the conduit 26 enters the heater there is provided a damper 30which may be adjusted to regulate the flow of gases therethrough. At thelower side of the heater substantially opposite the point where theconduit 26 enters there is provided a fresh air inlet 31 provided with aregulating damper 32.

In the operation of the device, gas and air are admitted at 17 and 18 inorder to give an infiammable mixture which is ignited and burns withinthe first combustion chamber 14 issuing from the right end thereof (asviewed in Fig. 5). The fan 21 operates to cause a suction of air throughthe ports 18 and also operates to cause a circulation through thehea-ter as explained before. The products of combustion acting as adrying medium are exhausted from the heater by the'fan 21 and blown intothe oven 23 at the bottom whence they pass upwardly through the ovendrying the articles 25. In cases where the articles 25 have been paintedwith lacquer, enamel, paint. or other substances so that during thedrying process they give off combustible vapors, the following operationtakes place. These combustible vapors are drawn out of theoven at thetop through the conduit 26 and enter the heater into chamber. Thecombustion in this first chamber has heated the outer walls of it andconsequently these combustible vapors entering through the conduit 26into the space 27 become heated. The draft through the lieatercaused bythe fan draws these combustible vapors into the second combustionchamber 28 where they become mixed with the burning gases issuing fromthe first combustion chamber; and thus they are ignited and burned inthe second combustion chamber. Any additional fresh air required to aidin combustion is admitted through the fresh air inlet 31 by means of thevalve 32. rIhe bafiie bricks 29 in the second combustion chamber 28cause a thorough mixing of the combustible vapors and gases entering theheater through the conduit 26 with the burning gases issuing from thefirst combustion chamber 14 so that such combustible gases and vaporscoming from the oven are completely burned up and thus all danger ofexplosion removed. The burning of' these combustible vapors alsofurnishes additional heat to the drying medium issuing from the heaterand consequently aids in the drying process and also effects a saving offuel.

There is also provided an automatic shutoff for the gas, and theconstruction and operation of this device will now be explained. Nearthe discharge end of the heater 10 there is provided a Swingable plateor vane 33 hinged at its upper edge on a mounting member as indicated by34. This vane, when the heater is not in operation, hangs in a verticalpositionas shown in Fig. 5. The vane is light enough, however, so thatwhen the heater is in operation, it will beswung up into thesubstantially horizontal position at the top of the heater as shown inFig. 4 by the flow of the gases through `the heater.

-The upper edge of the vane 33 is pivoted by means of a shaft 34extending through the heater. One end of this shaft out-side of theheater is provided with a short lug 35 which takes a vertical positionas shown in Fig. 4 when the vane is swung up against the top of theheater. On the pipe 20 carrying the gas to the heater there is provideda quick acting valve 36 controlled by a lever 37. To the end of thelever 37 there is attached a handle 38 and this lever 37 is also pivotedat 39 to the upper end of a piston rod 40 connected to a plunger in adash pot41 which may be of any suitable construction. At 39 there isalso pivoted a long arm 42 having at one end a notch 43 adapted to beengaged by the lug 35 on the shaft 34. This notch 43 is so spaced thatit ywill be thus engaged only when the handle 38 is raised sufficientlyto move the lever 37 to open the valve 36. When the lever 37 is down insubstantially horizontal position as shown in Fig. 1, the valve 36 isclosed. It is obvious that raisving the bananas to lift` the lever at oopen.'

Lezama i until 1t is engaged bythe lug 35 as Shown in Fig. 4.

In the operation of the device, the fan is lstarted first. The velocityof the gases through the 'heater swings the damper or vane 3 3'from itsvertical position to a horizontal position against the top of theheater. The handle 38 is then raised opening` the quick acting valve 36and this valve is held open by engagement of the notch 43 with the lug35. The gas issuing from thevnozzle 17 is then lighted and the properair adjustment given by regulation of the shutter 19. A window 44 isprovided near the discharge end ofthe heater in order to observe thecombustion. The damper 32 is regulated to admit any fresh alr as desiredin order to make com-plete combustion in the heater. If for any reasonthe fan should cease, to operate, the damper 33 w1ll fall,

' thus releasing the lug` 35'from the notch 43 allowing the handle 38 toldescend and close the gas valve 36. The dash pot 41 is pro# vided inorder to cushion the downward movement of the handle 348. Y

While Ihave shown and described cer- 1.

tain embodiments of my invention, it isfto 4be understood that it iscapable of many modifications. Changes, therefore, in the constructionand arrangement may be made without departing from the spirit and scopeof .the invention as disclosed in the appended claims, in which it is myintention lto claim all novelty inherent in my. invention 'as broadly aspossible in view ofthe prior art. What I claim as new, and desire tosecure by Letters Patent, is: 1

1. An apparatus of the character specified having an endless passagetherein, a blower for circulation of air 1n said passage, a

tion by thevaction of the blower, a cut-'off valve in said means adaptedfor manual opening independently of the vane and normally seeking aclosed position, anda connectlng means between said' valve and vane toautomatically engage the vane through opening movement of the valve tohold the valve -against closing influence.

2. In an apparatus of the character specified, a vane therein held inopen position by pressure within the apparatus, a fuel supp'ly pipe forthe apparatus having a cut-o valve, means opera le-manually to open thevalve independently of the movement of the vane, comprising a leverconnected to the valve, an arm member connected to the lever, said vanehaving a mounting member across which the arm member slides during Asaid movement, ,one of said members having a lug and the other memberhaving a notch adapted to engage .through said movement to hold thevalve against closing iniuence.

3. In an apparatus of the character specitied, a vane therein held inopen position by pressure within the apparatusn'a fuel supply pipe forthe apparatus having a cut-oli valve, means o erable manually to-openthe valve indepen ently of movement of the v ary, 1925.

FRAED P. MUEHLENBECK.

